Material handling apparatus such as mailpiece inserters or mailing machines commonly employ rollers and/or belts for transporting and separating/singulating sheet material. In the context used herein, “sheet material” is used generically to describe any substantially flat, two-dimensional media such as sheets of paper, postcards, laminate, mailpieces, etc. Oftentimes, a combination of belts and rollers (fixed or rotating) are employed, e.g., a roller opposing a set of belts, to separate/singulate individual sheets from a stack of sheet material.
A common singulating apparatus, used in a variety mailpiece inserters, employs one or more horizontal conveyor belts/rollers moving in one direction along a transport deck and at least one roller disposed above the belts to form a V-shaped ingestion area or throat between the rollers and the belt(s). In mailpiece inserters it is common to employ a stationary stone roller disposed a fixed distance above a conveyor belt/roller to define a gap which permits the passage of the lowermost sheet of material from a stack of sheet material. Alternatively, a drive roller may oppose the stone roller, immediately downstream of a conveyor belt to form the V-shaped throat for accepting sheet material from the conveyor belt. In other sheet handling apparatus, such as a mailing machine, a roller is similarly positioned above a conveyor belt/roller but is driven at a speed, or in a direction, which opposes the motion of the conveyor belt/roller to facilitate singulation of sheet of material. The roller(s), disposed above the driven belt/roller(s), are commonly mounted within a housing which includes an ingestion guide which is operative to prevent all but the lowermost sheets of a stack from approaching the ingestion throat, and an adjustment mechanism operative to define the singulation gap, i.e., the distance between the upper roller(s) and the underlying conveyor belt/roller, to accommodate sheets/mailpieces of various thickness. Hereinafter, the roller(s), housing, ingestion guide and adjustment mechanism will collectively be referred to as an “ingestion assembly” inasmuch as these elements are principally responsible for the ingestion/singulation of sheet material.
A variety of factors associated with the geometry and arrangement of the ingestion assembly can be difficult to control and/or to optimize the effectiveness of the singulating apparatus. For example, the ingestion assembly roller(s) must be precisely aligned with the underlying drive belt(s)/roller(s) to ensure that sheet material is reliably singulated, i.e., without skewing or damage to the singulated sheets. Furthermore, the singulation gap must be reliably and accurately controlled/maintained to reliably singulate the sheet material. That is, the ingestion assembly must be rigidly mounted above the drive belt(s)/roller(s) to maintain the singulation gap without deviation/variation. Furthermore, the ingestion assembly must be removable/detachable to access jammed sheet material from, or for the repair/maintenance of the underlying belt(s)/roller(s) of, the singulating apparatus.
Prior art ingestion assemblies are typically mounted to the deck of the singulating apparatus by a rigid box structure which spans laterally across the feed path, i.e., from one side of the singulating apparatus to the other. The box structure is typically fabricated from a high strength steel or aluminum and comprises several, high stiffness, cross members which rigidly suspend the ingestion assembly above the conveyor belt(s)/roller(s). Furthermore, the box structure and deck include precise mating surfaces, i.e., machined surfaces, to ensure accurate placement of the ingestion assembly. Finally, the box structure is attached to the deck by large set-screws/knobs which enable the structure to be detached and reassembled should a jam occur, or when repair/maintenance of the ingestion assembly or underlying belt(s)/roller(s) is required.
While this mounting arrangement provides the necessary rigidity, accuracy and flexibility to perform repair/maintenance, the box structure of the prior art is costly to fabricate and is cumbersome to assembly/reassemble, i.e., for such routine and, possibly frequent, activities associated with jam access and repair/maintenance.
A need, therefore, exists for a mounting arrangement which rigidly and accurately positions the ingestion assembly above the underlying conveyor belt(s)/roller(s) of the singulating apparatus while facilitating access, repair and maintenance.